func Curves(basis string, spans []int,
wrap string, varargs ...interface{}) {
pBasis := C.CString(basis)
defer C.free(unsafe.Pointer(pBasis))
pWrap := C.CString(wrap)
defer C.free(unsafe.Pointer(pWrap))
names, values, ownership := unzipArgs(varargs...)
defer freeArgs(names, ownership)
nArgs := C.RtInt(len(varargs) / 2)
nSpans := C.RtInt(len(spans))
pSpans := (*C.RtInt)(C.RtPointer(&spans[0]))
pNames, pVals := safeArgs(names, values)
C.RiCurvesV(pBasis, nSpans, pSpans,
pWrap, nArgs, pNames, pVals)
}
func unzipArgs(varargs ...interface{}) (names rtTokens,
vals rtPointers, owned rawPointers) {
if len(varargs)%2 != 0 {
fmt.Println("odd number of arguments")
return
}
nArgs := len(varargs) / 2
names = make(rtTokens, nArgs)
vals = make(rtPointers, nArgs)
owned = make(rawPointers, nArgs)
var pname string
for i, v := range varargs {
// Even-numbered arguments are parameter names
if i%2 == 0 {
if stringified, ok := v.(string); ok {
pname = stringified
token := C.CString(pname)
names[i/2] = token
} else {
fmt.Printf("argument %d is not a string\n", i)
return
}
continue
}
// Odd-numbered arguments are values
switch v.(type) {
case bool:
boolified := v.(bool)
var intified int32 = 0
if boolified {
intified = 1
}
vals[i/2] = C.RtPointer(&intified)
case int, int32:
intified := v.(int)
vals[i/2] = C.RtPointer(&intified)
case [3]float32:
floatified := v.([3]float32)
vals[i/2] = C.RtPointer(&floatified[0])
case [4]float32:
floatified := v.([4]float32)
vals[i/2] = C.RtPointer(&floatified[0])
case []float32:
floatified := v.([]float32)
vals[i/2] = C.RtPointer(&floatified[0])
case float32:
floatified := v.(float32)
vals[i/2] = C.RtPointer(&floatified)
case float64:
floatified := float32(v.(float64))
vals[i/2] = C.RtPointer(&floatified)
case string:
stringified := v.(string)
token := C.CString(stringified)
vals[i/2] = C.RtPointer(&token)
owned[i/2] = unsafe.Pointer(token)
default:
m := fmt.Sprintf("'%s' has unknown type %T\n", pname, v)
panic(m)
}
}
return
}